This invention relates generally to the field of fluid flow control devices and particularly to an energy efficient flow control device for the parenteral administration of medical fluid through an intravenous tube.
The usual procedure for the parenteral administration of fluids into the human body utilizes an intravenous set comprising a bottle of liquid supported in an inverted position, a flexible, clear plastic intravenous tube for delivery of fluid to the patient, a drip chamber and a suitable valve mechanism, such as a roller clamp attached to the tube to control the flow of fluid out of the bottle into a drip chamber below the bottle. The most simple way of controlling the fluid fed to a patient is to count the drops dripping into the drip chamber over a period of time, and to adjust roller clamp to provide the flow rate as needed.
Administration of the medical liquids by gravity in the aforesaid manner is subject to large flow rate variations due to a variety of well known causes and in recent years, sophisticated electronic monitoring systems and drop controllers have been developed to minimize such flow variations.
One very successful improvement in drop rate controllers is disclosed in U.S. Pat. No. 3,800,794 to H. W. Georgi (assigned to the present assignee) entitled METHOD AND APPARATUS FOR FLUID FLOW CONTROL. In this patent, an electronic system is described which controls the frequency at which a pincher opens and closes an IV tube to a relatively high multiple of the drop rate.
Another advance in the art is disclosed in U.S. Pat. No. 3,756,556 to H. W. Georgi (assigned to the present assignee) entitled FLUID FLOW CONTROL APPARATUS which describes an improved electromechanical device for controlling fluid flow.
The above inventions are embodied in infusion controllers (Models 230 and 260) manufactured by IVAC Corporation. While IVAC controllers embodying the Georgi inventions have been commercially successful, the need for even further improvement has remained. The present invention satisfies that need and provides a compact, quiet energy efficient flow controller having durability and long term accuracy.